A reluctance to open up to family members about issues at school or online

Becoming secretive about their internet use and the devices they are using to go online

(Source: Bully Zero Australia Foundation)

The teenagers were captivated by Michael's candour.

No-one was looking out the window or fiddling on their mobile phones. Instead they were transfixed by this emotional father's every word.

"The day after I found Jess, my eldest daughter Amy and myself started wondering what the hell had gone wrong," Michael continued.

"We still had her laptop and her iPad so we started looking through them and saw she had been cyber bullied the night before she died.

"Two people were telling her that she was a sook, that she should just get over things, that 'if you come around to my place, I'm going to slam the door in your face. You're useless'.

"There were 87 messages between the two and you could tell how hurt Jess was in the messages.

"She was pleading with them just to stop but they relentlessly just kept going."

Father using daughter's death to educate others

Michael Cleland recently signed up to be an ambassador with the Bully Zero Australia Foundation, a not-for-profit group supporting victims and raising awareness about the dangers and consequences of bullying.

The organisation's chief executive, Oscar Yildiz, who holds anti-bullying sessions at schools every week, said parents such as Michael Cleland were incredibly courageous in joining him.

"To have ambassadors who have actually been through a child's death after cyber bullying — they've been through that pain, they live the nightmare every day — to be able to express that to an audience of young teenagers is probably the most effective way of delivering these messages," he told 7.30.

"These parents are using the death of their own kids to educate others and we've got an army of these families.

"We are so appreciative that they're able to come out out of the goodness of their hearts. They don't get paid, they're all volunteers."

Mr Yildiz said he hoped emotional sessions, such as Michael Cleland's, would empower teenagers to carefully consider their online behaviour.

"When people start to feel something they change and I think a lot of these teenagers will leave this room this morning thinking 'I need to think twice about some of the messages I do write'," he said.

Ensure inappropriate images are removed by alerting social media networks and internet service providers

Consider parental controls and filtering software

Ensure your child has privacy controls set

Keep pins and passwords secret

(Source: Bully Zero Australia Foundation)

"It's like a woman saying, 'I want to dress in a certain way' and people say 'oh, if you go and dress like that you're putting yourself in danger' — you're sort of taking away their liberties.

"Why should Jess have given up something because somebody else misused it?"

Michael spoke directly to any cyber bullies in the audience too.

"It's so easy to sit behind a computer screen and type something nasty and push the send button and think 'ha, ha, I've done something,' but the consequences on the other end could be like us — it destroys a family," he said.

After the talk, many students stayed behind to thank, and hug, their guest speaker.

"People need to stop and realise that bullying is serious and it's taking people's lives because of other people's immature and childish actions."

Another student, Christian Cashia, said: "It does make me think more on what I say online and how I say it and what it means to other people and what it does to them mentally," .

Fellow student Matthew Ashton added: "I thought it was interesting how we got an experience from somebody whose daughter has actually killed herself, because I've never actually talked to someone who's been through that.

"You see it on TV and in films, but you don't actually get the real deal."

Michael admitted the morning was draining, but said he knew it was an important one for the students, and for himself.

"You could see that most of the kids were paying attention and were getting something out of it, which was a good feeling to know you're actually doing some good," he said.

"As long as something comes out of it and Jess's death wasn't just another death in the statistics, then that's what I was hoping to do."

When asked if he would do more school talks like the one at Glenroy College, Michael smiled and nodded.

You have no doubt been hearing a lot about the Paris Agreement and know that it pertains to climate change, but are too embarrassed at this stage to ask for an overall explanation of what it's all about.